It is becoming more common to replace a missing tooth with a prosthetic tooth that is placed upon and attached to a dental implant. Dental implants are often comprised of metal and metal alloys, including titanium (Ti) and titanium alloys. The dental implant serves as an artificial root that integrates with the gingiva and the bone tissue of the mouth.
For the dental implant to function successfully, sufficient osseointegration is required. In other words, a bond between the implant and the bone must be formed and retained. The surface of the implant may be roughened to help enhance the osseointegration process. Non-limiting examples of processes for roughening an implant surface include acid etching, grit blasting, or a combination thereof, which impart roughness on the surface.
Other existing techniques involve forming a generally thin (e.g., generally less than 10 microns) coating of osseointegration material(s), such as hydroxyapatite (HA), other calcium phosphates, or other osseointegration compounds, for forming a direct chemical compound between the implant and the bone. Plasma spraying and sputtering are two major techniques that have been used to deposit, for example, HA, onto an implant.
U.S. Pat. App. Pub. Nos. 2008/02200394, 2007/0110890, and 2007/0112353 disclose methods of discrete deposition of hydroxyapatite crystals to impart a nano-scale topography. Although effective, the disclosed processes require that a residual substance (i.e. HA crystals) be left on the surface post-processing in order to impart a nano-scale topography into the surface.
U.S. Pat. App. Pub. No. 2011/0233169 discloses methods of creating nanopitting on a microscale roughened surface by immersion of the microscale roughened surface into a solution containing both hydrogen peroxide and a basic solution.
The present invention is directed to an improved implant having a nanometer-scale web-like surface topography directly imparted into the surface for improving the rate and extent of osseointegration, and methods of making the same. The methods described herein create the nanometer-scale web-like surface on a microscale roughened surface by immersion of the microscale roughened surface into a solution including potassium hydroxide.